Abstract In this notebook, I take a look at the relationships between the returns on the Footsie, and those for the midcaps and the AIM over the last decade. I found that there is a strong correlation between the Footsie and the midcaps, but a weaker correlation to the AIM. The midcaps have tended to amplify the gains of the Footsie, but the AIM market has lost money over the last decade.
http://pdf.markcarter.me.uk/indices2014-12-15.html
For the very geeky out there, I have bundled the underlying ipython3 notebook and data in a zip file: http://pdf.markcarter.me.uk/indices2014-12-15.zip, so you can experiment with it if you wish.